Polishing apparatus



April 8, 1959 L. G. SIMJIAN 2,883,809

POLISHING APPARATUS Filed vNOV. 21, 1957 LUTHER G. SI MJIAN INVENTOR.

United States Patent POLISHING APPARATUS Luther G. Simjian, Greenwich,Conn., assignor to The Reflectone Corporation, Stamford, Conn., acorporation of Connecticut Application November 21, 1957, Serial No.698,015

7 Claims. (Cl. 51-281) This invention relates to polishing and hasparticular reference to the polishing of the surfaces of articles whichare formed with re-entrant cavities and other surfaces that arediflicult to polish by the usual rigid or semi-rigid polishing means.The invention is particularly related, as set forth below, to thoseinventions described in my U.S. Letters Patent No. 2,735,231 grantedFebruary 21, 1956, and No. 2,735,232, dated February 21, 1956.

This application is itself a continuation-in-part of my application forpatent, No. 566,571, filed February 20, 1956, now abandoned, in that Idisclose in this application the method as Well as the apparatus setforth in said application Serial Number 566,571. Since I disclose inapplication 566,571 and also in this application, the method firstdescribed in my application resulting in Patent No. 2,735,231, supra,granted February 21, 1956, with which said earlier application 566,571was co-pending. There are therefore in this application claims coveringthe method disclosed in said Patent No. 2,735,231. Further, the methodclaims of this application cover also the methods set forth in PatentNo. 2,735,232, supra, as well as my further Patent No. 2,787,854,granted April 9, 1957.

My invention is further related to that set forth in my applicationSerial No. 689,569 dated October 11, 1957, for an Abrading Device. Inthis last application a plurality of parts to be abraded are so abradedwhile held in a fluent bath merely by the magnetized particles of thebath, although in one form of the invention, other support means areshown.

In general machine shop practice, polishing is accomplished by anoperator using a bufling wheel which is rotated at high speed and whichhas been impregnated with a polishing compound. It is well known thatsuch a device gives fast and satisfactory results only on fiat or convexsurfaces. Concave surfaces, however, are more difficult to polish with apolishing wheel and small holes and cavities cannot be handled at allusing this conventional polishing means. The present invention can beused to polish almost any sort of surface including plane surfaces,holes, and other cavities, and does not require the use of an operator.

In a typical embodiment, the present invention utilizes a container thatcontains a mixture of abrasive magneic particles and a liquid. Thearticle to be polished or abraded is immersed in the mixture at a timewhen said mixture is not subjected to magnetic lines of force, or whensaid magnetic lines of force are so weak that said mixture is fluent.Naturally, when the mixture is subjected thereafter to magnetic lines offorce, it becomes non-fluent in proportion to the magnetization of saidmagnetic lines of force, and is operable to abrade the article immersedtherein. In the particular apparatus set forth in this application, thearticle to be polished or abraded, once applied to the mixture, is movedin and out of said mixture, or relatively to it. Naturally, movementrelatively to the mixture of the article when the mixture is relativelyless fluent, will bring about an Patented Apr. 28, 1959 abrading action,the degree of solidification or hardening of the mixture beingcontrolled by means of a magnetic field applied to the mixture.

Naturally, there can be intermediate conditions of the mixture as willbe appreciated by those skilled in the art. The more intense themagnetic lines of force, naturally, the harder will be the mixture. Bysynchronizing the mechanical motion of the object, and the applicationof the magnetic field to the mixture in such a manner that theconsistency of the mixture is increased whenever the article is movedrelatively to the mixture or otherwise manipulated relatively thereto,and immersing the article into the mixture when the mixture issubstantially liquid or otherwise more fluent than before, the surfaceof the article becomes polished. Since the mixture will readily followthe contours of the object when fluent, it is apparent that surfaces ofgears, jewelry, plastic molds and of many other articles can be polishedin a convenient, economic manner.

One of the objects of this invention is to provide an improved polishingdevice which avoids one or more of the disadvantages and limitations ofprior art arrangements.

Another object of the invention is to polish objects having smallcavities.

Another object of this invention is to polish complex structures withcomplete safety to the operator.

Another object of this invention is to polish an object without the aidof rotating wheels or belts.

Another object of the invention is to provide a polishing operationwhich is automatic and does not require the skill and judgment of atrained operator.

Another and further object of the invention is the provision of apolishing apparatus which produces uniform results.

A still further object of the invention is the provision of a polishingdevice which readily can be adjusted for various conditions of hardness,of speed and surface characteristics.

The basic feature of my invention is the control through magnetism of abath of abrasive material that is fluent when not magnetized, but whichis rendered non-fluent to varying degrees when subjected to magneticlines of force, all for the purpose of abrading an article. The articleto be abraded is placed in the bath of abrasive material when the bathis not substantially magnetized and is at least sufliciently fluent forthe placing of the article in the bath with the abrasive material of thebath moving into the recesses of the article to be abraded or polished.Thereafter, relative motion between the article and the bath effects theabrading action, it being, of course, possible to obtain this relativemotion by many means including actual motion of the particles ofabrasive material as the mixture is magnetized.

For a better understanding of the present invention together with otherand further objects thereof reference is made to the followingdescription taken in connection with the accompanying drawing in whichthe figure is a cross-sectional view of the polishing device,illustrating one typical embodiment.

Referring now to the figure, a container 10 preferably made ofnon-magnetic material is employed, filled with a mixture 11 whichcomprises abrasive magnetic particles, such as iron filings, steelpowder, powdered Alnico material, etc. mixed with a liquid, as forinstance oil. In proximity to said container there is located a magneticcore 12 having an electromagnetic coil 13 mounted thereon which whenenergized with electric current establishes a magnetic flux through themixture 11 so as to solidify it or increase its consistency.

Within said mixture 11 and intersecting the magnetic field, there isdisposed an object, the surface of which is to be polished, such asthree spur gears 14, which are retained on a stud 15. This stud is movedvertically by means of a motor 16 driving a wheel 17 connected via pin18 to a connecting rod 19 and coupling pin means 20.

The container and magnetic parts are surrounded by a housing 21 which isequipped with a top cover 22 in which there is disposed a bearing 23which serves to guide stud 15 in vertical position.

In synchronism with the motion of Wheel 17 there is being driven a cam30 which is employed to actuate an electrical circuit switch 31. Thiscircuit switch 31 serves as timing switch to energize electromagneticcoil 13 when the object is raised from the mixture and to deenergize thecoil when the object is lowered. In this manner, when the object ismoved out of the mixture, the magnetic particles by virtue of themagnetic field are urged in intimate contact with. the object andbecause of the increase of consistency of the mixture, an abradingaction of the particles against the object surface is achieved. In theconventional manner, drive motor 16 is energized from a source of energy35 via a control switch 34. Similarly the electric circuit to theelectromagnetic coil includes a source of energy 36 and a control switch37.

It will be apparent to those skilled in the art that the instant deviceis well suited for polishing complex surfaces since the mixture willshape itself to follow the contours of the object. By varying theparticle size of the mixture, the intensity of the magnetic field, etc.a great variety of conditions is achieved to satisfy the great majorityof prevalent conditions.

While there have been described certain embodiments of the instantinvention, it will be apparent to those skilled in the art that variousother modifications may be made without departing from the spirit of thepresent invention which should be limited only by the scope of theappended claims.

What is claimed is:

1. The method of abrading the surface of an article that comprisesplacing the article in a bath of magnetizable fluent material at a timewhen said magnetizable material is not magnetized and is thereforefluent to permit the insertion of the article thereinto with thesurfaces of the article to be abraded inundated in said bath,magnetizing said fluent material to render the bath non-fluent with themagnetizable material in intimate contact with the surfaces of thearticle to be abraded, and thereafter de-magnetizing and magnetizingsaid bath at predetermined intervals with the article movable in saidbath relatively to said fluent material while said fluent material isnot magnetized.

2. The method of abrading the surface of an article that comprisesplacing the article in a bath of magnetizable fluent material at a timewhen said magnetizable material is in that magnetic state rendering itsufliciently fluent to permit the insertion of the article thereintowith the surfaces of the article to be abraded inundated in said bath,magnetizing said fluent material to render the bath relativelynon-fluent with the magnetizable material held in intimate contact withthe surfaces of the article to be abraded, and thereafter de-magnetizingand magnetizing said bath to a predetermined degree at predeterminedintervals.

3. The method of abrading the surface of an article that comprisesplacing the article in a bath of magnetizable abrasive fluent materialat a time when said magnetizable material is in that magnetic staterendering it sufficiently fluent to permit the insertion of the articlethercinto with the surfaces of the article to be abraded inundated insaid bath, and the abrasive material flowing into intimate contact withinterior surfaces to be abraded, magnetizing said fluent material torender the bath nonfluent with the magnetizable material held inintimate contact with the surfaces of the article to be abraded, andmoving said article and said magnetized fluent material relatively toone another.

4. The method of abrading the surface of an article that comprisesplacing the article in a bath of magnetizable fluent material, applyingmagnetic lines of force to said fluent material to render the bath lessfluent than prior to the application of said magnetic lines of force andin proportion to the strength of the magnetic force so applied thereto,with the magnetizable material in intimate contact with the surfaces ofthe article to be abraded, and moving said article and said magnetizedfluent material relatively to one another.

5. The method of abrading the surface of an article that comprisesplacing the article in a bath of magnetizable abrasive fluent materialat a time when said magnetizable material is in that magnetic staterendering it sufficiently fluent to permit the insertion of the articlethereinto with the surfaces of the article to be abraded inundated insaid bath, and the abrasive material moving into intimate contact withthe surfaces to be abraded, applying magnetic lines of force to saidmagnetized fluent material to render the bath less fluent in accordancewith the strength of said magnetic lines of force, and moving thearticle and abrasive material relatively to one another to effect theabrading action.

6. The method of abrading the surface of an article that comprisesplacing the article in a bath of magnetizable abrasive fluent materialat a time when said magnetiz able material is in that magnetic staterendering it sufliciently fluent to permit the insertion of the articlethereinto with the surfaces of the article to be abraded inundated insaid bath and the abrasive material moving into intimate contact withthe surfaces to be abraded, magnetizing said fluent material to hold themagnetizable abrasive material firmly in intimate contact with thesurfaces of the article to be abraded, and moving the article and saidabrasive material relatively to one another to effect the abradingaction.

7. The steps in the method of abrading the surface of an article thatcomprise placing the article in a bath of magnetizable fluent materialat a time when said magnetizable fluent material is in that magneticstate rendering it sufiiciently fluent to permit the insertion of thearticle thereinto with the surfaces of the article to be abradedinundated in said bath, and the abrasive material flowing into intimatecontact with interior surfaces to be abraded, and thereafter magnetizingsaid fluent material to hold the magnetizable material in said intimatecontact with the surface of the article to be abraded whereby to makepossible the abrading of said surfaces.

References Cited in the file of this patent UNITED STATES PATENTS2,735,231 Simjian Feb. 21, 1956 2,735,232 Sirnjian Feb. 21, 19562,796,702 Bodine June 25, 1957

